Herein, we systematically investigated how to tailor correlative fluctuation and related properties in Ni–Nb–Zr metallic glasses (MGs). The Ni60Nb40-xZrx MGs (x = 0–20 at.%) with Nb–Zr atomic pair (ΔHmix=+4 kJ/mol) exhibited correlative atomic scale fluctuations in composition and topological orders upon Zr addition up to 20 at.% in XAFS analysis, which would, in turn, lead to fluctuations in local elastic properties. Interestingly, a statistical analysis of strain burst sizes along with in situ bending test showed that more effective elastic interaction between weak spots upon loading is promoted in Ni60Nb20Zr20, due to correlative atomic scale fluctuations, thereby resulting in multiple shear bands. The bulk specimens (d = 1 mm) for 8 and 10 at.% of Zr with increased glass-forming ability (GFA) exhibited enhanced plasticity without the reduction of fracture strength, implying cooling rate effect on fluctuation-induced plasticity. We believe that the results of this study would provide an effective guideline for tuning correlative fluctuation and related properties in MGs via manipulation of enthalpy relationship and cooling rate.
|Number of pages||9|
|Publication status||Published - 2019 Jul|
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (Ministry of Science, ICT and Future Planning) (No. NRF-2018M3A7B8060601 ). One of the authors (E.S. Park) also benefited from the Center for Iron and Steel Research (RIAM) and Institute of Engineering Research at Seoul National University. We are grateful to Pohang Light Source (PLS) for SAXS and XAFS measurements and Korea Basic Science Institute for valuable assistance with high voltage electron microscope. The author is indebted to Professor Frans Spaepen, Harvard University for thoughtful advice, especially about the bend test.
© 2019 Acta Materialia Inc.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Polymers and Plastics
- Metals and Alloys